document.write( "Question 94843: if f(x)=(2-xsquare)
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Algebra.Com's Answer #69624 by bucky(2189)\"\" \"About 
You can put this solution on YOUR website!
Given:
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\n" ); document.write( "\"f%28x%29+=+2+-+x%5E2\" <=== call this equation 1
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\n" ); document.write( "Next you need to find \"f%28x%2Bh%29\". What this means is you return to \"f%28x%29+=+2+-+x%5E2\" and
\n" ); document.write( "you replace every x in that equation with \"x%2Bh\". When you do that replacement you get:
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\n" ); document.write( "\"f%28x%2Bh%29+=+2+-+%28x%2Bh%29%5E2\" <=== call this equation 2
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\n" ); document.write( "To simplify this you need to square the \"x%2Bh\" on the right side. Do this by multiplying:
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\n" ); document.write( "\"%28x%2Bh%29%5E2+=+%28x%2Bh%29%2A%28x%2Bh%29+=+x%5E2+%2B2xh+%2B+h%5E2\"
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\n" ); document.write( "Substitute \"x%5E2+%2B2xh+%2B+h%5E2\" into equation 2 in place of \"%28x%2Bh%29%5E2\" and equation 2 becomes:
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\n" ); document.write( "\"f%28x%2Bh%29+=+2+-+%28x%5E2+%2B+2xh+%2B+h%5E2%29+=+2+-+x%5E2+-+2xh+-+h%5E2\" <=== call this equation 3
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\n" ); document.write( "The problem asked you to find \"f%28x%2Bh%29+-+f%28x%29\". From equation 3 we know that:
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\n" ); document.write( "\"f%28x%2Bh%29+=+2+-+x%5E2+-+2xh+-+h%5E2\"
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\n" ); document.write( "and from equation 1 we know:
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\n" ); document.write( "\"f%28x%29+=+2+-+x%5E2\"
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\n" ); document.write( "So we substitute the right side of these two equations into \"f%28x%2Bh%29+-+f%28x%29\" in place
\n" ); document.write( "of \"f%28x%2Bh%29\" and \"f%28x%29\" to get:
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\n" ); document.write( "\"f%28x%2Bh%29+-+f%28x%29+=+2+-+x%5E2+-+2xh+-+h%5E2+-+%282+-+x%5E2%29\"
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\n" ); document.write( "On the right side, since the set of parentheses are preceded by a minus sign, the parentheses
\n" ); document.write( "can be removed if we change the signs of the two terms in the parentheses. This makes the
\n" ); document.write( "equation become:
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\n" ); document.write( "\"f%28x%2Bh%29+-+f%28x%29+=+2+-+x%5E2+-+2xh+-+h%5E2+-+2+%2B+x%5E2%29\"
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\n" ); document.write( "Now on the right side you can notice that the +2 and the -2 cancel each other as does the
\n" ); document.write( "\"-x%5E2+\" and the \"x%5E2\". Those terms, therefore, disappear and you are left with:
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\n" ); document.write( "\"f%28x%2Bh%29+-+f%28x%29+=+-+2xh+-+h%5E2\"
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\n" ); document.write( "Hope this helps you to understand the problem a little more.
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